Hand-held transmitters have become fairly ubiquitous. Many people operate such transmitters to open and close garage doors, activate and deactivate security systems for automobiles, automated gates, and control a wide array of basic systems such as irrigation systems, and the like. A typical hand-held transmitter is battery powered and includes a transmitter that may be associated with a controller circuit, which contains the data that is transmitted from the system. Other, more complex systems may include receivers and other circuits designed for different functions. However, all of these functions draw power from the battery, which is typically provided with a single, non-renewable charge.
When the battery within a transmitter loses its charge, the transmitter loses or has diminished functionality. In many instances, this may mean that an individual is locked out of a garage or an automobile. This may prove to be more than a simple inconvenience, such as when an alarm system or irrigation system operates solely on remote controlled access. Typically, an individual is left with a transmitter having insufficient voltage to operate and no back-up batteries readily available. Carrying around a supply of batteries is impractical. Accordingly, users are forced to simply wait for the battery within the transmitter to expire due to a lack of adequate forewarning. Only with such forewarning can users safely and conveniently replace transmitter batteries prior to their expiration.
Various prior art transmitting devices have been provided with an audible or visual indicator to advise their users that power within the devices had nearly expired. However, such systems would only have nough power to warn users of a low battery condition, but not enough power to operate the device. Sometimes users have found themselves in situations that have made it inconvenient, if not impossible, to stop what they were doing and find a location that sells the right replacement battery. In such instances, the users have invariably needed to continue use of the transmitters as the low battery signal was activated. This has left the users wondering how many transmissions were possible with the existing battery, hoping the power would not expire before the need for the transmitter was satisfied. None of the prior art systems have provided multi-staged voltage status indications that permitted casual continued use of the transmitters without fear of the transmitters dying at the wrong time.
Another issue related to low battery conditions in portable transmitters has centered on the power demand of various transmitters. In many instances, transmitting devices are provided as multi-tasking devices that include, transmitters, receivers, controller circuits, lit displays, and the like. As such, use of such transmitters has depleted the battery supply more rapidly than single use transmitters. A last-minute low-battery warning to a user may be far too late to do any good. The power consumption needs of some transmitting devices would fully deplete a low voltage supply shortly after the low-battery warning could be issued.